GENERATING AND PROCESSING MAC-ehs PROTOCOL DATA UNITS

ABSTRACT

A wireless transmit/receive unit (WTRU) may disassemble enhanced high speed medium access control (MAC-ehs) protocol data units (PDUs) to provide reordering PDUs. A reordering PDU may include a MAC-ehs service data unit (SDU) or a segment of the MAC-ehs SDU. The WTRU may reassemble the MAC-ehs SDU from segments of the MAC-ehs SDU disassembled from a reordering PDU. The WTRU may route the reassembled MAC-ehs SDU to a logical channel of a plurality of logical channels.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/213,078 filed Mar. 14, 2014, which is a continuation of U.S. patentapplication Ser. No. 12/044,285 filed Mar. 7, 2008, which issued as U.S.Pat. No. 8,675,527 on Mar. 18, 2014, which claims the benefit of U.S.provisional application No. 60/893,577 filed Mar. 7, 2007, the contentsof which are hereby incorporated by reference herein.

FIELD OF INVENTION

The present invention is related to wireless communications.

BACKGROUND

High speed packet access (HSPA) evolution refers to the third generationpartnership project (3GPP) radio access technology evolution of highspeed downlink packet access (HSDPA) and high speed uplink packet access(HSUPA). Some of the major goals of HSPA evolution include higher datarates, higher system capacity and coverage, enhanced support for packetservices, reduced latency, reduced operator costs and backwardcompatibility.

It has been agreed that an enhanced high speed medium access control(MAC-ehs) entity is extended to include a function for segmentation andmultiplexing from different priority queues in addition to being able toreceive radio link control (RLC) protocol data units (PDUs) of flexiblesize. The addition of new MAC-hs functionalities requires modificationto the conventional MAC-hs architecture.

FIG. 1 shows a universal terrestrial radio access network (UTRAN) sideMAC-ehs entity 100 proposed for HSPA evolution. In the proposed MAC-ehsarchitecture, segmentation is performed per logical channel bysegmentation entities 112. The segmented MAC-ehs service data units(SDUs) are then multiplexed by the logical channel identity (LCH-ID)multiplexing entities 114 based on the logical channel identity, andbuffered in the configured priority queue 116. A MAC-ehs protocol dataunit (PDU) is then generated from the MAC-ehs SDUs stored in thepriority queue 116 and transmitted via a hybrid automatic repeat request(HARQ) entity 120.

FIG. 2 shows a user equipment (UE) side MAC-ehs entity 200 proposed forHSPA evolution. The received MAC-ehs PDU via an HARQ entity 202 isdisassembled into reordering PDUs by the disassembly entity 204. Thereordering PDUs are distributed to a reordering queue 208 by thereordering queue distribution entity 206 based on the received logicalchannel identifier. The reordering PDUs are reorganized according to thetransmission sequence number (TSN). Reordering PDUs with consecutiveTSNs are delivered to a higher layer upon reception. A timer mechanismdetermines delivery of non-consecutive data blocks to higher layers.There is one reordering entity 208 for each priority class. An LCH-IDdemultiplexing entity 210 routes the reordered reordering PDUs to areassembly entity 212 based on the logical channel identifier. Thereassembly entity 212 reassembles segmented MAC-ehs SDUs to originalMAC-ehs SDUs and forwards the MAC-ehs SDUs to upper layers.

The proposed MAC-ehs entity 100 for the UTRAN-side performs segmentationon a per logical channel basis. However, the segmentation of the MAC-dPDUs should not be performed at that level, since the packet will not betransmitted immediately. The multiplexed reordering PDUs are buffered inthe priority queue 116 and sent at a later time. Segmentation of theMAC-ehs SDUs prior to knowing the exact channel conditions isinefficient. The segmentation should not be performed prior to the timeinterval in which the packets will be transmitted. It would be desirablethat the segmentation be performed at the time when the MAC-ehs PDU iscreated and the size of the transport block (TB) for that transmissiontime interval (TTI) is known. In addition, if the UTRAN is updated tosegment the MAC-ehs SDUs right before the MAC-ehs SDUs are sent, theWTRU must also be updated accordingly.

In the proposed MAC-ehs entity 200 in FIG. 2, the LCH-ID de-multiplexingentity 210 routes the MAC-ehs segments to the reassembly entity 212based on the logical channel identity. This requires reassembly entitiesfor different logical channels within the same queue. In addition, ifMAC-ehs headers are optimized, the system information (SI) field willnot be present for every logical channel, but it will be present onlyfor the priority queue.

SUMMARY

A method and apparatus for generating and processing a MAC-ehs PDU aredisclosed. In a Node-B, MAC-ehs SDUs received from an upper layer aremultiplexed based on a logical channel identity. Reordering PDUs aregenerated from the multiplexed MAC-ehs SDUs from different logicalchannels mapped to a priority queue. A reordering PDU includes at leastone MAC-ehs SDU and/or at least one MAC-ehs SDU segment. A MAC-ehs SDUis segmented on a priority class basis if a MAC-ehs SDU does not fitinto a reordering PDU. A MAC-ehs PDU is generated including at least onereordering PDU. The multiplexed MAC-ehs SDUs may be stored in acorresponding priority queue before generating the reordering PDUs.Alternatively, the reordering PDUs may be generated from the multiplexedMAC-ehs SDUs and the reordering PDUs may be stored in a correspondingpriority queue. Alternatively, the received MAC-ehs SDUs may be bufferedin a corresponding buffer for each logical channel before multiplexedbased on a logical channel identity, or reordering PDUs are generated.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example and to be understood in conjunction with theaccompanying drawings wherein:

FIG. 1 shows a UTRAN-side MAC-ehs entity proposed for HSPA evolution;

FIG. 2 shows a UE-side MAC-ehs entity proposed for HSPA evolution;

FIGS. 3-4 show a UTRAN-side MAC-ehs entity in accordance with oneembodiment;

FIG. 5 shows a UTRAN-side MAC-ehs entity in accordance with anotherembodiment;

FIGS. 6-8 show a UTRAN-side MAC-ehs entity in accordance with anotherembodiment;

FIG. 9 shows a UTRAN-side MAC-ehs entity in accordance with anotherembodiment; and

FIG. 10 shows a WTRU-side MAC-ehs entity in accordance with oneembodiment.

DETAILED DESCRIPTION

When referred to hereafter, the terminology “wireless transmit/receiveunit (WTRU)” includes but is not limited to a UE, a mobile station, afixed or mobile subscriber unit, a pager, a cellular telephone, apersonal digital assistant (PDA), a computer, or any other type of userdevice capable of operating in a wireless environment. When referred tohereafter, the terminology “Node-B” includes but is not limited to abase station, a site controller, an access point (AP), or any other typeof interfacing device capable of operating in a wireless environment.

The terminology “MAC-ehs payload unit” or “payload unit” will refer to aMAC-ehs SDU or a MAC-ehs SDU segment that is inserted as a payload of aMAC-ehs PDU. The terminology “MAC-d flow” and “logical channel” are usedinterchangeably, and use of one term does not exclude the other. Theterminology “reordering PDU” refers to one unit of a MAC-ehs PDU. TheMAC-ehs PDU may include one or more reordering PDUs. The reordering PDUmay include one or more payload units. The MAC-ehs SDU may be a MAC-dPDU, MAC-c/sh/m PDU, or the like.

FIG. 3 shows a UTRAN-side MAC-ehs entity 300 in accordance with oneembodiment. The MAC-ehs entity 300 includes a scheduling and priorityhandling entity 310, an HARQ entity 320, and a transport format andresource combination (TFRC) selection entity 330. The scheduling andpriority handling entity 310 includes LCH-ID multiplexing entities 312,priority queues 314, segmentation entities 316, and a priority queuemultiplexing entity 318. The scheduling and priority handling entity 310manages HS-DSCH resources for data flows according to their priorityclass. The HARQ entity 320 handles HARQ functionality for supportingmultiple instances (HARQ process) of stop and wait HARQ protocols. TheTFRC selection entity 330 selects a TFRC.

The MAC-ehs entity 300 receives MAC-ehs SDUs from an upper layer, (e.g.,MAC-d or MAC-c entity (not shown)). The LCH-ID multiplexing entity 312may multiplex the MAC-ehs SDUs from multiple logical channels based onthe scheduling decision and the TFRC selected by the TFRC selectionentity 330 The TFRC selection entity 330 indicates to the scheduling andpriority handling entity 310 the size of the MAC-ehs PDU and thus thesize of data to be transmitted from each queue into a reordering PDU tobe transmitted on a TTI basis. The multiplexed MAC-ehs SDUs are storedin a priority queue 314.

The segmentation entity 316 may segment the MAC-ehs SDUs per priorityqueue. The segmentation entity 316 segments a MAC-ehs SDU if the MAC-ehsSDU does not fit into a reordering PDU. For example, if the MAC-ehs SDUto be included in the reordering PDU is greater than the size of thereordering PDU or it causes the sum of payload units to exceed the sizeof the selected reordering PDU, the segmentation entity 316 segments theMAC-ehs SDU. In this case, the reordering PDU includes only one segmentof the MAC-ehs SDU. The remaining segment of the MAC-ehs SDU aftersegmentation is stored in the segmentation entity and may be transmittedas the first payload unit in the next reordering PDU for the priorityqueue if the remaining segment fits into the next reordering PDU. Theremaining segment of the MAC-ehs SDU is segmented again if the remainingsegment still does not fit into the next reordering PDU. This may berepeated until all the parts of the MAC-ehs SDU have been transmitted.The reordering PDU will contain at most two segments, one at thebeginning and one at the end, and may include zero, one, or more thanone complete MAC-ehs SDUs.

The segmentation entity 316 may base its segmentation decision on thecurrent channel condition, the given transport format and resourcecombination (TFRC) selection, the reordering PDU size, and the like. Thesegmentation is performed on a priority queue basis instead of on a perlogical channel basis.

The priority queue multiplexing entity 318 may perform multiplexing ofreordering PDUs in one MAC-ehs PDU. The priority queue multiplexingentity 318 selects one or more reordering PDUs from one or more priorityqueues 316 in order to create the MAC-ehs PDU based on the TFRCselection.

The priority queue multiplexing entity 318 may be incorporated into theHARQ entity 320. The TFRC selection entity 330 may be attached to thescheduling and priority handling entity 310, as shown in FIG. 4.

FIG. 5 shows a UTRAN-side MAC-ehs entity 500 in accordance with anotherembodiment. In this embodiment, the segmentation is performed on apriority queue basis after logical channel multiplexing. The MAC-ehsentity 500 includes a scheduling and priority handling entity 510, anHARQ entity 520, and a TFRC selection entity 530. The scheduling andpriority handling entity 510 includes LCH-ID multiplexing entities 512,segmentation entities 514, priority queues 516, and a priority queuemultiplexing entity 518. The scheduling and priority handling entity 510manages HS-DSCH resources for data flows according to their priorityclass. The HARQ entity 520 handles HARQ functionality for supportingmultiple instances (HARQ process) of stop and wait HARQ protocols. TheTFRC selection entity 530 selects a TFRC.

The MAC-ehs entity 500 receives MAC-ehs SDUs from an upper layer. TheLCH-ID multiplexing entity 512 may multiplex MAC-ehs SDUs from multiplelogical channels based on the scheduling decision and optionally basedon the TFRC selected by the TFRC selection entity 530. The TFRCselection entity 530 indicates to the scheduling and priority handlingentity 510 the size of the MAC-ehs PDU to be transmitted on a TTI basis.

The MAC-ehs SDUs, after the logical channel multiplexing, may besegmented by the segmentation entity 514. The segmentation entity 514segments a MAC-ehs SDU if the MAC-ehs SDU does not fit into a reorderingPDU based on the TRFC selection. The reordering PDU contains at most twosegments, one at the beginning and one at the end, and may include zero,one, or more than one MAC-ehs SDUs.

Reordering PDUs are stored in a priority queue 516. The priority queuemultiplexing entity 518 may perform multiplexing of reordering PDUs inone MAC-ehs PDU. The priority queue multiplexing entity 518 selects oneor more reordering PDUs from the priority queues 516 in order to createthe MAC-ehs PDU.

The priority queue multiplexing entity 518 may be incorporated into theHARQ entity 520. The TFRC selection entity 530 may be attached to thescheduling and priority handling entity 510.

FIG. 6 shows a UTRAN-side MAC-ehs entity 600 in accordance with anotherembodiment. In this embodiment, the MAC-ehs SDUs are buffered perlogical channel and segmentation is performed on a priority queue basisafter logical channel multiplexing. The MAC-ehs entity 600 includes ascheduling and priority handling entity 610, an HARQ entity 620, and aTFRC selection entity 630. The scheduling and priority handling entity610 includes queues 612, LCH-ID multiplexing entities 614, segmentationentities 616, priority handling entities 618, and a priority queuemultiplexing entity 619. The scheduling and priority handling entity 610manages HS-DSCH resources for data flows according to their priorityclass. The HARQ entity 620 handles HARQ functionality for supportingmultiple instances (HARQ process) of stop and wait HARQ protocols. TheTFRC selection entity 630 selects a TFRC.

The MAC-ehs entity 600 receives MAC-ehs SDUs from upper layers. MAC-ehsSDUs are stored in queues 612 on a logical channel basis. Alternatively,the queues 612 may not be present and data from different logicalchannels may flow directly from upper layers to the corresponding LCH-IDmultiplexing entities 614. The LCH-ID multiplexing entities 614multiplexes MAC-ehs SDUs stored in the queues 612 or received from thecorresponding logical channels based on scheduling decision, schedulingpriority and the TFRC selected by the TFRC selection entity 630. Basedon the TFRC selection and the selected reordering PDU size, the MAC-ehsSDUs may be segmented by the segmentation entity 616. The segmentationentity 616 segments a MAC-ehs SDU if the MAC-ehs SDU does not fit into areordering PDU. For example, if the MAC-ehs SDU to be included in thereordering PDU is greater than the size of the reordering PDU or itcauses the sum of payload units to exceed the size of the reorderingPDU, the segmentation entity 316 segments the MAC-ehs SDU. In this case,the reordering PDU includes only one segment of the MAC-ehs SDU. Theremaining segment of the MAC-ehs SDU after segmentation is stored in thesegmentation entity 616 and may be transmitted as the first payload unitin the next reordering PDU for the priority queue if the remainingsegment fits into the next reordering PDU. The remaining segment of theMAC-ehs SDU is segmented again if the remaining segment still does notfit into the next reordering PDU. This may be repeated until all theparts of the MAC-ehs SDU have been transmitted. The reordering PDUcontains at most two segments, one at the beginning and one at the end,and may include zero, one, or more than one MAC-ehs SDUs.

The priority handling entity 618 defines relative priorities betweensets of logical channels (and/or MAC-d flows), and optionally assignsTSNs. The priority queue multiplexing entity 619 performs multiplexingof reordering PDUs in one MAC-ehs PDU.

The priority handling entity 618 and its functionalities may beincorporated in the priority queue multiplexing entity 619, as shown inFIG. 7, (i.e., priority queue multiplexing and TSN setting entity 702).The segmentation entity 616 or the LCH-ID multiplexing entity 614 may beextended to buffer segments of the MAC-ehs SDUs. The TFRC selectionentity 630 may be attached to the scheduling and priority handlingentity 610, as shown FIG. 8.

FIG. 9 shows a UTRAN-side MAC-ehs entity 900 in accordance with anotherembodiment. In this embodiment, the MAC-ehs SDUs are buffered perlogical channel. Alternatively, the queues 912 may not be present anddata from different logical channels may flow directly from upper layersto the corresponding segmentation entities 914. Segmentation isperformed per logical channel on a TTI basis after the buffering. TheMAC-ehs SDUs are buffered per logical channel rather than per priorityqueue. The MAC-ehs entity 900 includes a scheduling and priorityhandling entity 910, an HARQ entity 920, and a TFRC selection entity930. The scheduling and priority handling entity 910 includes queues912, segmentation entities 914, LCH-ID multiplexing entities 916,priority handing entities 918, and a priority queue multiplexing entity919. The scheduling and priority handling entity 910 manages HS-DSCHresources for data flows according to their priority class. The HARQentity 920 handles HARQ functionality for supporting multiple instances(HARQ process) of stop and wait HARQ protocols. The TFRC selectionentity 930 selects a TFRC.

The MAC-ehs entity 900 receives MAC-ehs SDUs from upper layers. MAC-ehsSDUs from logical channels, (or MAC-d flows), are stored in queues 912for each logical channel or alternatively are directly delivered fromupper layers without any buffering. The MAC-ehs SDUs may then besegmented by the segmentation entity 914. The segmentation entity 914segments a MAC-ehs SDU if the MAC-ehs SDU does not fit into a reorderingPDU as selected by the TFRC selection. The reordering PDU contains atmost two segments, one at the beginning and one at the end, and mayinclude zero, one, or more than one MAC-ehs SDUs. The LCH-IDmultiplexing entity 916 then multiplexes reordering PDUs from multiplelogical channels, (i.e., multiple MAC-d flows), based on the schedulingdecision and the TFRC selected by the TFRC selection entity 930.

The priority handing entity 918 defines relative priorities between setsof logical channels (and/or MAC-d flows), and optionally assigns TSNs.Alternatively, the TSNs setting may be performed per logical channelinstead of per priority queue. The priority queue multiplexing entity919 performs multiplexing of reordering PDUs in one MAC-ehs PDU. Thepriority handling entity and its functionality 918 may be incorporatedin the priority queue multiplexing entity 919. Alternatively, the LCH-IDMUX and priority queue multiplexing may be combined in one entity andmultiplexing may be performed only on one level, on a logical channelbasis.

The segmentation entity 914 or the LCH-ID multiplexing entity 916 may beextended to buffer outstanding segments of the MAC-ehs SDUs. The TFRCselection entity 930 may be attached to the scheduling and priorityhandling entity 910.

FIG. 10 shows a WTRU-side MAC-ehs entity 1000 in accordance with oneembodiment. Since in the UTRAN may perform segmentation aftermultiplexing logical channels in the mapped priority queue, theconventional WTRU-side MAC-ehs entity is modified to reflect thesechanges and to perform the reassembly and de-multiplexing in the sameorder. If segmentation is performed on a per priority queue basis,reassembly should be based on the reordering queue segmentationinformation.

The MAC-ehs entity 1000 includes an HARQ entity 1002, a disassemblyentity 1004, a reordering queue distribution entity 1006, reorderingqueues 1008, SDU disassembly entities 1010, reassembly entities 1012,and LCH-ID demultiplexing entities 1014. The transmitted MAC-ehs PDUsare received via the HARQ entity 1002. The disassembly entity 1004disassembles the MAC-ehs PDU to reordering PDUs. The reordering queuedistribution entity 1006 distributes the reordering PDUs to anappropriate reordering queue 1008 based on the logical channel identity.The reordering PDUs are reordered at the reordering queue 1008 based onthe TSN. The SDU disassembly entity 1010 disassembles MAC-ehs SDUs andsegmented MAC-ehs SDUs from the reordered reordering PDUs, and deliversthem to the reassembly entity 1012. The reassembly entity 1012reassembles segmented MAC-ehs SDUs to original MAC-ehs SDUs for everyreordering PDU and forwards the completed and reassembled MAC-ehs SDUsto the LCH-ID demultiplexing entity 1014. The LCH-ID demultiplexingentity 1014 routes the complete MAC-ehs SDUs to the correct logicalchannel, or MAC-d flow. Optionally, the SDU disassembly entity 1010 andthe reassembly entity 1012 may be combined to one entity.

Although the features and elements of the present invention aredescribed in the preferred embodiments in particular combinations, eachfeature or element can be used alone without the other features andelements of the preferred embodiments or in various combinations with orwithout other features and elements of the present invention. Themethods or flow charts provided in the present invention may beimplemented in a computer program, software, or firmware tangiblyembodied in a computer-readable storage medium for execution by ageneral purpose computer or a processor. Examples of computer-readablestorage mediums include a read only memory (ROM), a random access memory(RAM), a register, cache memory, semiconductor memory devices, magneticmedia such as internal hard disks and removable disks, magneto-opticalmedia, and optical media such as CD-ROM disks, and digital versatiledisks (DVDs).

Suitable processors include, by way of example, a general purposeprocessor, a special purpose processor, a conventional processor, adigital signal processor (DSP), a plurality of microprocessors, one ormore microprocessors in association with a DSP core, a controller, amicrocontroller, Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs) circuits, any other type of integratedcircuit (IC), and/or a state machine.

A processor in association with software may be used to implement aradio frequency transceiver for use in a wireless transmit receive unit(WTRU), user equipment (UE), terminal, base station, radio networkcontroller (RNC), or any host computer. The WTRU may be used inconjunction with modules, implemented in hardware and/or software, suchas a camera, a video camera module, a videophone, a speakerphone, avibration device, a speaker, a microphone, a television transceiver, ahands free headset, a keyboard, a Bluetooth® module, a frequencymodulated (FM) radio unit, a liquid crystal display (LCD) display unit,an organic light-emitting diode (OLED) display unit, a digital musicplayer, a media player, a video game player module, an Internet browser,and/or any wireless local area network (WLAN) module.

What is claimed is:
 1. A method performed by a wireless transmit/receiveunit (WTRU), the method comprising: receiving, by the WTRU via a highspeed downlink shared channel (HS-DSCH), enhanced high speed mediumaccess control (MAC-ehs) protocol data units (PDUs); disassembling, bythe WTRU, the MAC-ehs PDUs to provide reordering PDUs, wherein at leastone reordering PDU includes a MAC-ehs service data unit (SDU) or asegment of the MAC-ehs SDU; organizing, by the WTRU, the reordering PDUsbased on at least one transmission sequence number (TSN); reassembling,by the WTRU, the MAC-ehs SDU from segments of the MAC-ehs SDUdisassembled from at least one of the reordering PDUs; and routing thereassembled MAC-ehs SDU to a logical channel of a plurality of logicalchannels.
 2. The method of claim 1, wherein the receiving of the MAC-ehsPDUs is performed by a hybrid automatic repeat request (HARQ).
 3. Themethod of claim 1, wherein the disassembling is performed by adisassembly entity.
 4. The method of claim 1, wherein the organizing isperformed by a reordering queue distribution function or a reorderingqueue.
 5. The method of claim 1, wherein the reassembling is performedby a reassembly entity.
 6. The method of claim 1 further comprising: thereassembling reassembles segmented MAC-ehs SDUs to a different MAC-ehsSDU for every reordering PDU.
 7. The method of claim 1, wherein thereordering PDUs each comprise a complete MAC-ehs SDU and segments ofMAC-ehs SDUs.
 8. A wireless transmit/receive unit (WTRU) comprising:circuitry configured to receive, via a high speed downlink sharedchannel (HS-DSCH), enhanced high speed medium access control (MAC-ehs)protocol data units (PDUs); circuitry configured to disassemble theMAC-ehs PDUs to provide reordering PDUs, wherein at least one reorderingPDU includes a MAC-ehs service data unit (SDU) or a segment of theMAC-ehs SDU; circuitry configured to organize the reordering PDUs basedon at least one transmission sequence number (TSN); circuitry configuredto reassemble the MAC-ehs SDU from segments of the MAC-ehs SDUdisassembled from at least one of the reordering PDUs; and circuitryconfigured to route the reassembled MAC-ehs SDU to a logical channel ofa plurality of logical channels.
 9. The WTRU of claim 8, wherein thereception of the MAC-ehs PDUs is performed by a hybrid automatic repeatrequest (HARQ).
 10. The WTRU of claim 8, wherein the disassembly isperformed by a disassembly entity.
 11. The WTRU of claim 8, wherein theorganization is performed by a reordering queue distribution function ora reordering queue.
 12. The WTRU of claim 8, wherein the reassembly isperformed by a reassembly entity.
 13. The WTRU of claim 8 wherein: thecircuitry is further configured to reassemble segmented MAC-ehs SDUs toa different MAC-ehs SDU for every reordering PDU.
 14. The WTRU of claim8, wherein the reordering PDUs each comprise a complete MAC-ehs SDU andsegments of MAC-ehs SDUs.